011. Effects of extended operative time on surgical and hospital outcomes after posterior spinal fusion for adolescent idiopathic scoliosis

Authors: Benjamin C Reeves

Extended operative time (EOT) has been associated with increased complication rates and longer hospital stays (LOS). However, there is a paucity of data investigating the impact of EOT in adolescent idiopathic scoliosis (AIS) patients undergoing deformity correction surgery.Methods: A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database from 2016-2018. All patients aged 10-18 years undergoing PSF for AIS were identified using the ICD-9-CM and ICD-10-CM coding system. Patients were categorized by operative time: Non-EOT and EOT - those with an operative time >75th percentile for the overall patient population. Multivariate regression analysis was used to determine risk-factors for EOT and impact on LOS.
A total of 4,632 patients were identified, of which 24.5% had an EOT. Age and comorbidities were similar between the cohorts. The EOT cohort had more 13+ level fusions (EOT: 38.9% vs. Non-EOT: 17.8%, p < 0.001) and a greater total amount of blood transfused (EOT: 420.6 ± 361.4 mL vs. Non-EOT: 244.5 ± 217.2 mL, p < 0.001). Compared to the Non-EOT cohort, the EOT cohort had higher rates of complications (EOT: 2.9% vs. Non-EOT: 1.0%, p < 0.001) and 30-day readmission (EOT: 4.2% vs. 2.2%, p=0.006), as well as a longer mean LOS (EOT: 4.0 ± 1.2 days vs. Non-EOT: 3.6 ± 1.1 days, p < 0.001). On multivariate analysis, Asian race, ASA classification 2 and 3, anesthesia start duration, levels fused and total blood transfused were found to be a significant independent risk-factors for EOT. Additionally, EOT was found to be a significant predictor for prolonged LOS [RR: 0.26, 95% CI: (0.16, 0.36), p < 0.0001].
Our study found EOT associated with increased complications and longer LOS. Further studies are needed to corroborate these findings so as to optimally risk-stratify patients pre- and post-operatively.